Keil ULINK USB device not usable.

Description

Linux host, Windows target. I plug this device with usb id c251:2710, I changed the whole /proc/bus/usb to owner the user running vbox. I removed all the filter but on the usb devices list available this device appeared as uknown and grayed where on previous vbox versions, the device was perfectly usable.

Someone at the #vbox channel suggested me that there could be a problem in the parser for the usb devices causing thus the problem.

With VirtualBox 1.5.4 something regarding USB changed. Make sure that all files in /proc/bus/usb/*/* are writable by the user running VBox and /proc/bus/usb/devices is at least readable. Unfortunately, it is no longer possible to verify easily if a device could work or not using a user-provided /proc/bus/usb/devices file. So please check yourself if VirtualBox 1.5.4 solves your USB problem.

Make sure that you drop/merge all snapshots/saved states of every VM before you upgrade.